sqlの四捨六入5対の関数(1)

--drop function MyRound
create   function   MyRound(@num   numeric(20,10),@i   int) 
--@i       
--@num      
returns   varchar(20) 
as 
begin 
declare   @numtemp   numeric(20,10)
declare   @result   varchar(20) 
set   @numtemp=abs(@num)*power(10,@i+1) 
select   @numtemp=(case   when   floor(@numtemp)-floor(@numtemp/10)*10=5 
                                            then   (case   when   @numtemp-floor(@numtemp)=0 
                                                                  then   (case   when   cast(floor(@numtemp/10)   as   int)%2=0 
                                                                                        then   floor(@numtemp/10)/power(10,@i) --        5，     ，      
                                                                                        else   round(@numtemp/power(10,@i+1),@i)--         5，     ，      
                                                                                          end) 
                                                                  else   round(@numtemp/power(10,@i+1),@i) --        5,       
                                                                  end) 
                                              else   round(@numtemp/power(10,@i+1),@i) --         5
                                              end) 
set   @result=(case   when   @num> 0   then   str(@numtemp,20,@i)   else   str(0-@numtemp,20,@i)   end) 
return   @result 
end